Patent GB-501619-A (GB)
Title: Improvements in electric welding apparatus
IPC: B23K9/32
Filed: 1937-10-28
Abstract: 501,619. Uniting by fusion. LINDE AIR PRODUCTS CO. Oct. 28, 1937, No. 29441. Convention date, Feb. 6. [Class 83 (iv)] In an electric are welding apparatus using a bare wire electrode, particularly for carrying out the process described in Specifications 433,723 ; and 438,855, [Group II], in which the end of a metallic electrode is submerged under a blanket of inorganic high resistance welding material or flux, means is provided to vary as desired the amount of dry flux fed to the are so that this may be maintained in amount sufficient to surround the are and cover the molten metal produced thereby. The welding head comprises a pair of slotted casings 10 which contain a number of independently screw-adjusted straight - ening rolls S and are secured to a bracket 18, Fig. 8, bolted to the casing G of the reducing gear to which the casing of the motor M is secured. Two parallel shafts 40 projecting from the casing G form the pivots of housings 38, in which the feed rolls R for the electrode E are mounted, the rolls being connected by gears 44, 42 to the shafts 40. The housing 38 are pressed together by a spring 60 through a sleeve 56 and headed rod 50, which is adjusted by a threaded socket 62. The housings are centred by a right and left-hand screwed rod 66, Fig. 5, provided with collars 76 engaging un open slotted member 7S secured to the casing G. the screws engaging threaded collars 74, 75 loosely mounted in reccesses in the housings 38. The feed rolls may be provided with grooves 522 having spaced teeth 524, Fig. 30, or may be made of a pair of blanks screwed together and provided with V-shaped teeth 532, Fig. 32. An insulated tube 86 secured in an arm 84 attached to the casing G carries a pair of plates. 90 to one of which is secured a plate 96 to which are secured the electric-conductors 100 and also a fixed grooved contact jaw 102. The other plate 90 carries a support 92, Fig. 4, for a spring 116 which is connected to the end of a lever 108 pivoted in un ear 104 on the plate 96 and having loosely bolted thereto the movable grooved contact jaw. 112. A flexible conductor 118 connects the plate 96 to the movable jaw 112 to provide an independent current carrying path thereto. The electrode wire may be in coil form mounted on a reel expansible to suit the diameter of the coil. The reel which is mounted on a shaft 124, Fig. 7, provided with an adjustable brake 134, consists of a screwed sleeve 148, held on the shaft by a screw and washer 152 and provided with recesses to receive a number of radially slotted tubes 160 secured to a backing plate 164. The tubes contain arms 166 which are radially adjusted by pivoted telescopic arms 180 carried by a ring 182 engaging a threaded hand wheel 156. The telescopic arms are held in adjusted position by removable pins. On the rods 166 are carried fixed brackets 168 and also brackets 174 which may be moved on their pivots for assembly of the coil. Spacers 184 may also he provided. The seam guide may comprise a pair of wheels 246, Fig. 8, carried by links 244 on a member 242 adjustabje by racks 238 and pinions on a shaft geared to a hand operated shaft 230. The gearing is mounted in a bracket 226 secured to the motor casing. In this form the casing may be suspended from the shaft 214 of a hanger 210 on a fixed or travelling support so that it may swing laterally in response to irregularities in the seam. The head may be rigidly fixed to the shaft 214 by a clamp 218, particularly when the end of the seam is approached. If desired, the work may be moved relatively to the machine. The work may rest on a fluid cooled backing member. In another form the guide wheels 246, Fig. 12. may be connected by springs 296 and the links 244 secured as desired in a series of holes 282 in a block 278 which may be laterally adjusted by a screw in guides so as to be laterally offset from the centre line of the electrode when welding on a circular line or when welding a bevelled plate to a straight plate. When making circumferential welds in pipes the links may be attached to different holes 282 to suit the curvature of the pipe. In another form. Fig. 16, the wheels may he replaced by a ball 342 or wedge-shaped head carried by a screw 344 threaded into a member 346 spring- mounted in a sleeve 352, which is secured to an arm 357 used instead of the block 278. The ball end may be of various sizes to suit the angle of bevel or thickness of work. In cases when the plates arc not bevelled the guide wheel 246, Fig. 21, may be replaced by or combined with a guide wheel 366 engaging the plate edge. The wheel 366 is carried by a right-angled arm 358 slidably mounted in the plate 242<1> and passing through an arm 360 secured to the block 278 and is pressed against the work either by spring 374 or spring 376. In making a fillet weld between two plates at an angle u grooved wheel 246<11>, Fig. 28, may be used to clear a tack weld, the edges of the wheel being bevelled to engage the respective plates. This wheel is mounted at the end of a spring- controlled bent arm pivoted on the block 278. The guide wheel may control hydraulic or electrical means for moving the apparatus laterally. In the former case the support 390, Fig. 23, for the welding apparatus carries a tank 392, motor 394, pump 396, and cylinders 418, 424 provided with a piston rod 422 secured by a bracket 426 to the welding apparatus. The latter carries a control valve 410, which is operated by an arm 442 connected by pin-andslot to an arm on the rod 430 carrying the guide wheel 246<1>. Rotation of the rod due to irregularities in the seam operates the valve so as to connect either cylinder 424, 418 to pressure supply. When pressure is not forced into the cylinders it returns to the tank through a pipe 406. The electrical operation of the apparatus may be effected by a motor 444 and a screwed shaft 446. In this case the guide wheel 246<1>, Fig. 25, is loosely mounted on a shaft 448 carried by a forked support 450. The wheel is straddled by a yoke 452 separated by springs from the support 450, the yoke having a contactor 456 which may engage one of three contacts 458, 460, 462 connected to a control relay 464 to which the motor and source of supply are also connected. The direction of rotation of the motor is dependent on the connection of the contact 456 to either of contacts 458 or 462. Granular welding material is supplied to the seam from a hopper 248, Fig. 8, secured to the apparatus and provided with butterfly valves. The hopper is partitioned so that one portion may contain new material and the other unfused material reclaimed from an earlier stage of the process. The outlets from the hopper are provided with flexible tubes 256, which as shown in Fig. 8, may be secured through tubes 258 to an adjustable plate 262 and project between a pair of Z-shaped plates 266 connected by links 268 to the plate 242 and provided with laterally adjustable plates for determining the width of the layer of welding material. In the form shown in Figs. 12 and 13 the tubes are connected by bayonet joints 310 to tubes 300 fixed in sleeves 298 to which are pivoted at 315 angle shaped brackets 314, which are adjusted by arcuate slots 318 and wing bolt 320 passing through the ends 316 of the brackets. The sides of the parts 314 are grooved and slotted to receive pairs of overlapping gates 328, which are provided with projections 330 passing through the slots 326 and secured by nuts 332, so that two separate chambers are provided. The butterfly valves 334 are operated by arms 336 fixed in position by retractable pins 338 passing through holes 340. In order to adjust the vertical position of the chambers they may be connected at 480, 482, Fig. 26, to two pairs of levers 472, 474, pivoted at 476 and 478 and the latter of which have bent extensions 486 to form a handle. The parts may be maintained in adjusted position by a latch 492 and toothed extension 494 of the plate 242 the spacing of the teeth being such as to allow of a limited vertical motion to provide for unevenness of the surface of the work. In fillet welding as in Fig. 28, the distributing-chambers are omitted. When making circumferential welds the parts 314 may be cut to correspond to the shape of the work. The apparatus may be provided with an attachment for reclaiming the unfused portion of the welding material during the progress of the operation. For this purpose the copper 248,. Fig. 33, is provided with an extension 542 connected by a tube 544 to a twopart hopper 546, 550, the upper part of which is connected at 562 to a suction device. A pipe 564 has a nozzle 566 in the vicinity of the work and unfused material is drawn into the hopper 546 which has a rubber lining and a handoperated valve 556. When the valve 556 is opened the material drops through the screen 568 'and when the sliding control gate 570 is opened it is supplied to hopper 248.